1. Field of the Invention
The present invention relates generally to a method and apparatus for exchanging information in a communication system. More specifically, the invention relates to a technique for obtaining caller-originated alert signals in IP-based communication sessions.
2. Description of the Related Art
The present evolution of data-communication is such that more and more users gain access to the Internet worldwide. The Internet has become both a source of knowledge but also a marketplace for business, and it is attracting more and more users. Currently there is a high pressure on the data-communications industry to provide solutions that allow everyone to gain access to Internet. Broadband solutions are continuously developed and both local as well as national access networks are planned and launched. The presently most common method of modem access through the telecommunications network (e.g., the Public Switched Telecommunication Network, PSTN provider) is being replaced by other ways of access with a possibility to higher data rates, e.g., through electric power and cable TV providers.
At the same time, the telecommunications industry is struggling another battle; that of providing mobility to each and every user. Traditionally, telecommunication has been focused on voice communication. With the increase of data communication however, other demands are arising (e.g., higher data rate transfer), but also new possibilities. Evolutions of mobile systems are presently in a period when more and more packet-based systems will be deployed. Packet switched systems have, in contrast to circuit switched systems, certain advantages when it comes to transfer of data-communication. In a packet switched system, a user is only utilizing a transmission resource when system control signaling or user information is transmitted. In a circuit switched system, a user is allocated a transmission resource continuously, even though no current transfer is active. Circuit switched systems have some obvious advantages in real-time voice communication, since it is difficult to predict the communication. For data-communication, it is not as important to predict the transmission resources required, since the demands on delay and delay variations are not as crucial to the communication quality as for voice. It is therefore possible to allow more users onto the transmission resources by allowing usage thereof only when there is something to transmit and leave the channel available for additional users otherwise.
One such system is the packet data evolution of the mobile communication system pursuant to the ETSI GSM specification, called General Packet Radio Service (GPRS). With GPRS, higher bit rates and more users may be allowed than what is possible today, when data communication is deployed on a circuit switched channel. GPRS is a step towards mobility for data communication users, in contrast to GSM, which is optimized for mobility for “traditional” telecommunication users, i.e., real-time voice communication users.
The data-communication run over the telecommunications networks today is usually initiated by an access to an Internet—or a mail server. A user logs on to a distant server and accesses the data-communications network through, e.g., modem pools. The user dials up the modem pool and is therefore connected to a server, from which access can be made to both local as well as global networks. Browsers like e.g., Microsoft Explorer or Netscape Navigator are used to navigate on the Internet and switch between Internet pages or addresses. Users and institutions usually design their own data objects, or homepages, on an internal or external network that provides personal information or any other kind of information. Once connected to the data network a user may access these data objects by entering the correct address. The address is often selected by combining a node name in the network (e.g., server name) and an arbitrary text-string. Typically, it is not trivial to find a desired data object, since the text strings and server names are not obvious.
Addressing in a telecommunications network, e.g., when engaging in a voice communication is usually performed by entering a telephone number on a User Equipment (UE), like a mobile telephone. A telephone number is a world-wide, unique addressing string. A calling party (A-party) dials the addressing string (B-number) to the called party (B-party). Dependent on what type of network the A-party is a subscriber on, the call request is routed through one or several public telecommunication networks to the correct addressee and the communication may begin.
The above principle also applies when a user wishes to connect to the Internet from a computer connected to a telecommunications network. The user connects to a data-communications network by dialing a B-number to a modem pool, from which accessing the data-communications network is possible. There are no information or interaction possibilities with the called server other than this access opportunity.
Applicants have identified that there is a problem in the present way of accessing the Internet for specific data objects because of the non-obvious way of addressing data objects. There is further a need in the telecommunications industry to provide a simpler way of accessing the Internet and to guide a user by other means than a modem number to call, from where the user is left on her own to be further guided to the desired homepage or data object.